1. Field of the Invention
This invention relates to diaphragm assemblies for railroad cars, and more particularly concerns diaphragm assemblies for connecting together the ends of railroad passenger cars.
2. Description of the Prior Art
Conventional diaphragm assemblies for connecting the ends of passenger railroad cars are a sandwich of steel plates and foam materials and typically comprise a thick core or section of foam material of rubber or synthetic resin that provides a spring-like resilience to the diaphragm assembly, a thin cover over the foam material to protect it from damage, a metal mounting plate which is fixed to the inner end of the foam section for attaching it to the end of a railroad car, a metal channel which is fixed to the outer end of the foam section to maintain its shape and to provide a mounting surface for a rubbing strip, and a rubbing strip of low-friction material which is mounted on the metal channel to provide a contact surface that rubs against a similar contact surface of an abutting diaphragm assembly on an adjoining railroad car.
A problem with conventional prior art diaphragm assemblies is that it is costly to fabricate the different components from different materials and to assemble them together.
Another problem with the prior art diaphragm assemblies is that their foam core is subject to damage by vandalism or by flying stones. The foam material itself is easily damaged and must have a flexible cover to protect it. This cover must be thin enough to enable the foam material to flex, but the thinness of the cover makes it vulnerable to damage.
Yet another disadvantage of the prior art diaphragm assemblies is that they combine the cover, which may be a rubberized fabric, with metal parts. If the cover is made of rubber and the rubber is black, it cannot be colored easily. The metal must be painted and the painted surface is subject to scratches and may need to be repainted.